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In a word, the simple answer to this question is no. Algae serves a vital role in the health of your pond, providing both natural filtration and food for fish and wildlife. Algae also looks aesthetically pleasing in a pond, provided there’s not too much of it.

To better understand algae’s place in your pond, it’s important to know the different types that are common. First, there’s filamentous algae. Often referred to as “pond scum,” growth of filamentous algae typically begins on the pond bottom. As it grows, it rises to the surface, and can quickly spread to cover the entire pond if not controlled.

String algae is the second variety of algae pond owners will invariably come to know. Essentially a variation on filamentous algae, this algae isn’t harmful, but its rapid growth can quickly take over the pond if it’s not controlled. Frequently seen on rocks in waterfalls, string algae has been known to double its mass in 24 hours when conditions are right – leaving little room for beneficial algae growth, and inhibiting the growth of beneficial bacteria and plants.

Where filamentous alga are generally unwelcome in most ponds, planktonic algae is its beneficial counterpart. Planktonic algae generally thrives within the first few feet from the surface, where it relies on light for photosynthesis – and produces food for microscopic pond dwellers and newly-hatched fry. While typically desirable in ponds, planktonic algae can bloom, and some forms can be toxic to animals. In those circumstances, special measures may be necessary to control its growth.

In order to maintain a healthy balance of algae growth in your pond, there are a few simple steps that go a long way. First, consider our Airmax® KoiAir™ and PondAir™ Water Garden Aeration Systems to ensure sufficient aeration. Stagnant water is an open invitation for excessive algae growth. Even if you have a waterfall, consider adding one to increase water circulation. For more aggressive algae treatment, our an algaecide such as AlgaeFix® to kill the algae and then follow up with the Pond Logic® DefensePAC®. And as a precautionary measure, consider adding a selection of Aquatic Plants to help maintain your pond’s equilibrium, to reduce excessive algae-promoting sunlight, and to provide safe havens for fish.